#CasearChineseEncode.py
ptxt = input('请输入明文文本：')
for p in ptxt:
    if 'a' <= p <= 'z':
        print(chr(ord('a') + (ord(p)-ord('a')+3)%26),end = '')
    elif 'A' <= p <= 'Z':
        print(chr(ord('A') + (ord(p)-ord('A')+3)%26),end = '')
    elif 0x4E00 <= ord(p) <= 0x9FA5:
        print(chr(ord(p)+3),end = '')
    else:
        print(p,end = '')
